<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script src="http://libs.baidu.com/jquery/2.0.0/jquery.js"></script>
	</head>
	<body>
		<div style="width: 200px;height: 200px;background-color: blueviolet;">这是一个测试啊</div>
	</body>
	<script>
		setTimeout(function(){
			$("div").css({"height":"800px"});
		},3000)
	</script>
</html>
